Fps is proud to present the first lightweight piston with a technopolymer body and all metal teeth equipped with a shock-absorbing system ZERO-SHOCK 100% Made in Italy. This system patented by Fps allows the stresses that the rack transmits to the piston body to be attenuated, making the assembly enormously more resistant and reliable than a normal piston.The material of the body has been studied a technopolymer filled with the addition of a small percentage of elastomer which gives high mechanical performances and a very low friction coefficient. The rack was manufactured using MIM (Metal Injection Molding) technology since this production process guarantees dimensional precision and robustness practically equal to those of solid machining.The rack comes with the second tooth missing and with the third already lowered by 3 tenths of a millimetre, as this configuration prepares the piston itself for a correct angle of engagement (AOE) and makes it suitable for high burst speeds.The type of metal injected it is the SAE 4650 surface treated with HRC38-42° hardening which is currently considered the best material on the market for this type of use.The sliding guides are designed to minimize friction and retain the lubricant for a long period of time. The seat of the rack is decentralized to favor the coupling between the teeth of the piston and those of the sector gear.The longitudinal reinforcements on the sides of the teeth increase the robustness of the piston and avoid contact of the rack with the wall inside the cylinder. Special ribs reduce the contact surface between the spring and the internal part of the piston body and consequently the friction between the metal and the technopolymer is also reduced during the contraction and elongation due to the firing cycle.
